1. Field of the Invention
The present invention relates to a communication terminal adaptor to be used between a communication terminal such as a facsimile apparatus and a telephone network.
2. Related Background Art
An automatic dialer for telephone line (hereinafter referred to simply as autodialer) is a device present between a communication terminal such as a telephone unit with contracted dialing function or a facsimile apparatus of G3 format and a telephone network, for decoding the content of said contracted dialing and automatically dialing to the destination based on thus decoded in format ion.
Such conventional autodialer is provided with a memory for registering information for transmission, and sends a continuous signal in the form of a PB (push button) signal or a DP (dial pulse) signal to the telephone network, based on said information for transmission, when a key of the autodialer is manually operated or when the autodialer is activated from an operation of the terminal.
However, such conventional autodialer is designed, in case of transmitting the information registered in said memory to the telephone network, so as to release a group of information elements in the form of a continuous signal as explained above, so that the PB signal and the DP signal cannot be used in mixed manner in a group of information elements. Thus, if transmission of information by the PB signal is required in a communication channel for the DP signal, it is necessary to make connection with the destination by the autodialer with a DP signal and then to send the PB signal from the terminal.
Also in a VAN (value-added network) service or a server unit, in designating the service thereof or the ID information with a DTMF (dual-tone multifrequency) signal in the form of PB signal, it is often required to confirm a short signal (hereinafter called tone prompt signal) released from such apparatus, prior to the transmission of the DTMF signal. In such case, with the conventional autodialer, it is necessary to make the connection with the destination by the operation of said dialer, then to confirm the tone prompt signal transmitted from the telephone network by the terminal, and to transmit the DTMF signal from the terminal.